55617231 has 4 divisors (see below), whose sum is σ = 74156312. Its totient is φ = 37078152.

The previous prime is 55617227. The next prime is 55617239. The reversal of 55617231 is 13271655.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 55617231 - 2² = 55617227 is a prime.

It is a super-2 number, since 2×55617231² = 6186552768214722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55617239) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9269536 + ... + 9269541.

It is an arithmetic number, because the mean of its divisors is an integer number (18539078).

Almost surely, 2^55617231 is an apocalyptic number.

55617231 is a deficient number, since it is larger than the sum of its proper divisors (18539081).

55617231 is a wasteful number, since it uses less digits than its factorization.

55617231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18539080.

The product of its digits is 6300, while the sum is 30.

The square root of 55617231 is about 7457.6960919576. The cubic root of 55617231 is about 381.7125634840.

Adding to 55617231 its reverse (13271655), we get a palindrome (68888886).

The spelling of 55617231 in words is "fifty-five million, six hundred seventeen thousand, two hundred thirty-one".